Systems and methods for testing ignition properties of particles

Abstract

Systems and methods for testing ignition properties of particles in a gas. Systems include a test chamber sized to hold a particle to be tested, a gas supply configured to deliver a gas to the test chamber, a heating device configured to heat the particle, and data acquisition equipment configured to collect data associated with the particle and/or the gas. Methods include generating a flow of gas around a particle that is fixed in space relative to the flow of gas in a test chamber, heating the particle and/or heating the gas, and collecting data associated with the particle and/or the gas.

The invention claimed is: 
     
       1. A method for testing ignition properties of particles, the method comprising:
 generating a flow of a gas around a particle that is fixed in space relative to the flow of the gas in a test chamber, wherein the particle is in the flow of the gas; 
 heating the particle to a desired temperature; and 
 collecting data associated with the particle and the flow of the gas. 
 
     
     
       2. The method of  claim 1 , further comprising selecting the gas, the flow of the gas, the particle and the desired temperature to correspond to a predefined scenario to be simulated, wherein the predefined scenario to be simulated includes a scenario associated with a hot particle moving through a gas. 
     
     
       3. The method of  claim 2 , wherein the predefined scenario to be simulated includes an aerospace scenario. 
     
     
       4. The method of  claim 1 , wherein the gas is a combustible gas. 
     
     
       5. The method of  claim 4 , wherein the heating results in combustion of the combustible gas, and wherein the collecting data includes collecting data associated with the combustion of the combustible gas. 
     
     
       6. The method of  claim 1 , wherein the gas consists essentially of a non-combustible gas. 
     
     
       7. The method of  claim 1 , wherein the flow of the gas is at a rate in the range of 0-500 m/s relative to the particle. 
     
     
       8. The method of  claim 1 , wherein the flow of the gas is at a pressure that is less than 1 bar. 
     
     
       9. The method of  claim 1 , wherein the generating the flow of the gas includes drawing a vacuum within the test chamber, inserting a volume of the gas into the test chamber to achieve a predetermined pressure of the gas, and imparting the flow to the gas. 
     
     
       10. The method of  claim 1 , wherein the generating the flow of the gas is facilitated by a closed-loop wind tunnel that includes the test chamber. 
     
     
       11. The method of  claim 1 , wherein the generating the flow of the gas includes recirculating the gas through the test chamber. 
     
     
       12. The method of  claim 1 , wherein the particle has a largest dimension in the range of 10-1000 microns. 
     
     
       13. The method of  claim 1 , wherein the particle is a metallic particle. 
     
     
       14. The method of  claim 1 , wherein the heating the particle includes heating the particle with a laser. 
     
     
       15. The method of  claim 1 , wherein the heating the particle includes heating the particle with infra-red light. 
     
     
       16. The method of  claim 1 , wherein the heating the particle includes conducting heat from a particle holder. 
     
     
       17. The method of  claim 1 , wherein the desired temperature is in the range of 25-4000° C. 
     
     
       18. The method of  claim 1 , wherein the collecting data includes one or more of visually observing the particle, visually recording the particle, measuring a temperature of the particle, measuring a velocity of the flow of the gas around the particle, measuring a pressure of the flow of gas, collecting time data, and collecting schlieren images associated with the flow of the gas around the particle. 
     
     
       19. The method of  claim 1 , further comprising:
 storing the data in a database; and 
 repeating the generating, the heating, the collecting, and the storing for different particles, wherein the different particles have different sizes or are comprised of different materials. 
 
     
     
       20. The method of  claim 1 , further comprising:
 storing the data in a database; and 
 repeating the generating, the heating, the collecting, and the storing for different gases. 
 
     
     
       21. The method of  claim 1 , further comprising:
 storing the data in a database; and 
 repeating the generating, the heating, the collecting, and the storing with one or more of different velocities of the flow of the gas around the particle, different pressures of the flow of the gas around the particle, and different temperatures of the particle. 
 
     
     
       22. The method of  claim 1 , wherein the generating the flow of the gas includes maintaining a laminar flow of the gas in the test chamber with the particle in the laminar flow of the gas. 
     
     
       23. The method of  claim 1 , wherein the generating the flow of the gas is facilitated by a closed-loop wind tunnel that includes the test chamber, and wherein the generating the flow of the gas includes:
 drawing a vacuum within the test chamber; 
 inserting a volume of the gas into the test chamber to achieve a predetermined pressure of the gas; 
 imparting the flow to the gas; 
 recirculating the gas through the test chamber; and 
 maintaining a laminar flow of the gas in the test chamber with the particle in the laminar flow of the gas. 
 
     
     
       24. A method for testing ignition properties of particles, the method comprising:
 generating a flow of a combustible gas around a particle that is fixed in space relative to the flow of the combustible gas in a test chamber, wherein the flow of the combustible gas is at a pressure that is less than 1 bar, wherein the particle is in the flow of the combustible gas, and wherein the particle has a largest dimension in the range of 10-1000 microns; 
 heating the particle to a desired temperature; 
 collecting data associated with the particle and the flow of the combustible gas; 
 storing the data in a database; and 
 repeating the generating, the heating, the collecting, and the storing for different particles and with different gases, wherein the different particles are comprised of different materials. 
 
     
     
       25. A testing system for testing ignition properties of particles, the testing system comprising:
 a test chamber sized to hold a particle to be tested; 
 a gas supply configured to deliver a gas to the test chamber; 
 a particle holder configured to hold the particle in a flow of gas in the test chamber and to hold the particle in a fixed position relative to the flow of gas around the particle; 
 a heating device configured to heat the particle to a desired temperature; and 
 data acquisition equipment configured to collect data associated with the particle and/or the gas.